The invention relates to a method for providing a desired output torque or an internal-combustion engine, in which deviations or an air mass flow, as measured by means or an airflow sensor, from the air mass flow actually supplied to the combustion chamber or the engine as they occur in dynamic operating states are compensated for by means or a load filter.
German Offenlegungsschrift 3,924,922 discloses a traction force control for an internal-combustion engine, in which, for each operating cycle, the difference between a predetermined desired intake-air quantity and the actually measured intake-air quantity per engine revolution is determined and the throttle-valve opening angle is corrected on the basis of this signal.
Moreover, German Offenlegungsschrift 3,940,681 discloses a throttle-valve position-regulating device, in which the deviation of the intake-air quantity, as measured by means or an airflow sensor, from a preset command-air quantity is determined. In addition, this mass-flow control includes a feedback control which varies the throttle-valve position in such a way that the deviation is reduced to zero, with a correcting element or the first order for compensating for the delay in the determination or the airflow sensor.
A disadvantage of these arrangements is that deviations which occur in dynamic operating states as a result of time-dependent pressure changes in the intake pipe and in the combustion chamber are not taken into account. Although, in the second arrangement, a correction is provided for the intake-air quantity determined by the airflow sensor, this correcting element of the first order can compensate only for the delay in the determination of the airflow sensor.
The object of the present invention is, therefore, to provide a method of controlling the torque generated by an internal-combustion engine in which the throttle-valve opening angle is corrected in such a way that, in dynamic operating states of the internal-combustion engine, the deviation of the torque actually provided from the predetermined desired torque is minimized.